The distinction between short form and long form is a development that stems from the going awry or misunderstanding the focus of a game. These terms get bandied about as if they are two separate disciplines. They are not.
Spolin used these games as exercises to help players enter into that space where who, what and where merge into spontaneous theater.
Once players are able to establish and maintain the focus, the game will take as long as it takes. All plays and short scenes are about solving of problems. Scenes have problems that combine to make a play. The play presents a larger canvas to house the individual scenes.
The short form, or simple game, if misunderstood, allows actors to resist the focus and use their heads to make something ‘stage-worthy’. Gimmicks, jokes and the other stuff people complain about in this work is just a simple avoiding of the true focus.